A lamp having gas filling is known from EP 1 471 564 A2. The LED lamp described therein is formed from a solid light source, which is installed on a carrier structure. A light-permeable vessel encloses the light source and carrier structure and an electrical input lead and return lead are fed into and out of the housing in order to supply the light source with electrical energy. A filling gas with a low molecular weight, such as helium or hydrogen, is enclosed in the vessel, which is in thermal contact with the light source.
This known LED lamp uses the thermal conductivity of helium for efficient cooling of the LED, wherein the heat is transported via the helium filling to the vessel walls. However, one drawback of the helium filling is the high price of this gas, while cheaper gases, such as, for example, hydrogen and nitrogen, have poorer heat conduction. Better heat conduction can be achieved by mixing these gases with air, but this results in an explosive mixture leading to undesirable vessel breakages. In addition, helium places high requirements on the tightness of the vessel.